21x21x1 MERV 13 Plus Carbon AC Furnace Filters 6 Pack plant-support Random start uses an algorithm

Random start uses an algorithm that will start the ballasts within a 0-15 second window

improve root systems

Telescopic pole extends lopper to 96-inches (2438mm)

Perfect for Large or Small Grows

5 stainless steel tank

21x21x1 MERV 13 Plus Carbon AC Furnace Filters 6 Pack plant-support Random start uses an algorithmNordic Pure Custom MERV 13 Plus Carbon air filters are made based on the actual measurements so be sure to measure your current filter to get the EXACT dimensions before ordering. As with all Nordic Pure filters, the effective life of your filter depends on the environment in which you live. We recommend changing 1 and 2 filters every 30 90 days. Our 4, 5 and 6 inch thick filters could last up to 6 months. EXACT MEASUREMENT: Furnace and air condition